7800991 has 8 divisors (see below), whose sum is σ = 8581968. Its totient is φ = 7090600.

The previous prime is 7800973. The next prime is 7800997. The reversal of 7800991 is 1990087.

It is not a de Polignac number, because 7800991 - 2⁵ = 7800959 is a prime.

It is a Duffinian number.

7800991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7800997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1600 + ... + 4261.

It is an arithmetic number, because the mean of its divisors is an integer number (1072746).

Almost surely, 2^7800991 is an apocalyptic number.

7800991 is a deficient number, since it is larger than the sum of its proper divisors (780977).

7800991 is an equidigital number, since it uses as much as digits as its factorization.

7800991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5894 (or 5872 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 7800991 is about 2793.0254205789. The cubic root of 7800991 is about 198.3276468173.

The spelling of 7800991 in words is "seven million, eight hundred thousand, nine hundred ninety-one".